全班50个人，俩个人生日在同一天的概率是？Java

package helloworld;
import java.util.Random;
public class hello {
public static void main(String[] args) {
for(int i = 0; i < n; ++i){
boolean[] p = new boolean[365];
for(int j = 0; j < 365; ++j) p[j] = false;
for(int k = 0; k < 50; ++k){
Random r = new Random();
int x = r.nextInt(365);
if(p[x]) {
cnt++;
break;
}
else p[x] = true;
}
}
System.out.println(cnt * 1.0 /n);
}
static int cnt = 0;
static int n = 10000;
}